Eliminator screen for evaporative towers and the like



May 13, 1958 M. L. GHAI ET AL' ELIMINATOR SCREEN FOR EVAPORATIVE TOWERSAND THE LIKE Filed Sept. l. 1955 2' Sheets-Sheet Mw ?ka Joseph .a. KarenBY m 77 g ATTOR G VENTO 72 L I I I I I .l v

May 13, 1958 M. L. GHAI ET AL 2,834428 ELIMINATOR SCREEN FOR EVAPORATIVETOWERS AND THE LIKE Filed Sept. l, 1955 2 Sheets-Sheet 2 3 .Ji/[adam 9gYoseph, A, Karen,

INVENTOR E Ga? United %States ELIIMINATOR SCREEN FOR EVAPORATIVE TOWERSAND THE LIKE Madan L. Ghai, Manchester, and Joseph A. Karen, Hartford,Conn., assignors, by mesne assignments, to Dunham-Bnsh, Inc., WestHartford, Conn., a corporation' of Connecticut Application September 1,1955, Serial No. 532,()54 8 Claims, (CI. 183-75) ticles from an airstream. A further object-is to remove. particles from an air stream orthe like with minimum' statc pressure drop and in an efiicient,dependable manner. A further object is to imp'ove the operation ofcooling towers and the like 'by providing for the removal ot waterparticles from the air stream in an improved manner. A further object isto provide improved structures and methods for removing water particlesfrom theair in such a way as to avoid the difficulties which have beenencountered in the past. A still further object is to provide for theabove with structure which is simple and sturdy, inexpensive tomanufacture and install, readily se'viced, and dependable and efiicientin use. These and other objects Will be in part obvious and in partponted out below.

In the drawings:

Figura 1 is a side elevation of a cooling tower incorporating oneembodiment of the invention, with parts broken away; i

Figure 2 is a somewhat enlarged View on the line 2-2 of Figure 1;

Figure 3 is an enlarged fragmentary View showing the details of thestructure of Figures 2, 4 and 5, and the mode of operation;

Figure 4 is an enlarged sectional view on the line 4-4 of Figure 3; and,

Figura 5 is a sectional view on the line 5-5 of Figure 3.

In refrigeration systems of a size greater than the order of three tonsCapacity, it has been increasingly common practice to provideevaporative cooling towers. With such apparatus, water is sprayed into afast movng stream k of air to evaporate water and dissipate heat. Thewater may be circulated from the tower to the condenser of therefrgeration system or the condenser of the refrigeration system may belocated in the tower. are frequently positioned upon a roof or elsewherehigh above the ground. Frequently, such towers have been consideredobjectionable because of the noise which they produce and also becauseof the tendency for such towers to expel water particles in the airstream which passes from them. The most serious object to such towersoften comes from people who pass near the tower within range of theescapng water particles. In the past, attempts have been made to removeall the particles from the air stream,

but this has involved the provison of the air-escape louvers whichpassed the air in thin streams along zig; zag paths. Such arrangementsare apt to increase materially the static pressure drop in the airstream so that Such towers zemres Patnted May 13, ?358 the aircirculation is reduced unless fan equipment was enlarged. However, theenlargement of the fan equipment tends to increase the powerrequirements and the cost of operation; and, it also increases the noiseproduced by the unit. It is among the objects of the present inventionto overcome these problems and to avoid the difiiculties which have beenencountered with this type of apparatus in the past. This isaccomplished by providing an improved eliminator screen structure forremoving water particles from the air stream passing from the coolingtower.

Referring particularly to Figure l of the drawings, an evaporativecooling unit 2 has a finned condenser coil 4 positioned within a casing6 and cooled by simultane-` ously passing water and a stream of airthrough it. The stream of air is drawn in at the right at 8, passeshorizontally and somewhat upwardly through the coil 4, and is dischargedat the left through an air dscharge opening 10 by a fan 12 driven by amotor 14. Water is supplied to` coil 4 from a distributor pan 16 whichis rectangular and has bottom openings from which small streams of waterpass. The water is intercepted and dispersed by a Water distributorscreen 18 and -covers the entire "face of coil 4. The water fiowsthrough coil 4 downwardly and the right; and, some of the water isevaporated, and the remainder is collected in a bottom sump and isrecirculated 'by a pump not shown.

The air passing from the conclenser coil 4 has been and has 'becomesaturated with moisture, and it also contains considerable water in theform of small particles. The present invention is concerned primarilywith the removal of these small particles of water from the air.Accordngly, an elininator screen 20 is positioned between theecondensercoil 4 and fan 12, and all of the air passing. to the fan fiows throughthis eliminator screen. This eliminator screen is constructed as shownbest in Figure 2, and has a rectangular wooden frame 22 with sideupright members, top and bottom members 26,` and a central uprightmember 28. Stapled to the two side faces of frame 22 are two identicalscreens 30 and 32 which are formed of thin sheet metal which has beenfabricated in a manner discussed below to provide water eliminatnglouvers.

The louver Construction 'constitutes vertical rows 34 of louvers 38having slots 39 therebetween, and between the rows 34 are verticalimperforate strips 36. louver construction is' shown best in Figures 3,4, and 5, where a portion of a row 34 is shown, together with theadjacent imperforate strips 36. In this connection, the screen isconsidered from the face shown in Fignre 5, which is positioned towardthe oncoming stream of air during operation. The individual louvers 38are flat strips of the sheet metal integral at their ends with theimperforate strips 36. The louvers extend longitudinally at an angle of45 to the horizontal, and they also are 'twisted from the original planeof the sheet metal to inwardly (see Figure 5), but the louver maintainsits original fiat condition.

Also, the left-hand end of each louver (that is, the lower end) ispositioned outwardly so that it extends somewhat above the originalplane of the 'sheet metal, whereas at the opposite (i. e., upperright-hand) end the louver is somew-hat depressed. Hence, each louverextends from the top from somewhat below the original plane of the sheetmetal downwardly and to the left, and through this plane. Each of theimperforate strips 36 between the two rows of louvers is provided with avertical channel or trough 46 which (see Figure 4) is somewhat an open-Vin cross section, and this is below The the level o'f the original planeof the sheet metal. As indicated above, there are 'two iden'ticlscree'ns "50 "ana 32, and the relationship between these two screens isdistance apart.

The louver-forming operation involves lcuttin'g,paral le'l slits 'into.the sheet metal along the side edges of the louvers 'being formed, 'andthe 'forming .tools simultaneously push the lower edge o'f each louveroitwardty, and the upper edge of each lonver inwardly. The operaton alsoincludes the forming of the troughs 46. Illustrafively, these eliminatorscreens are fabricated from strips of brass .008 inch thick andsubstantially 8inc hes Wide. After the .louver Construction has beenformed, the 'individual strips are s'tapled together a't ;their ed'gesto form the entire assembledtscreen.

'In this embodiment, the channels .are spaced ;if an 'inch apar't,center 'to center, and the width of the strip forming each of 'thevertical channels is substantially inch. Hence., the width of .each rowof louvers is inch. Hence, each of the louvers is of alength ofsubstantially one inch. i I

During operation, 'the stream of air .approaches the eliminator screenfrom the bottom o'f/Figure 4 toward the face o'f screen 30, shownin'Figure 3. The louvers'tend to divertthe air somewhat upwardly throughthe Slots 39 and these Slots are ofsufficent size to permit:Satisfactory flow of the air. However, particles of water entrained inthe .air stream .are fimpacted'aganst athe louvers and they cling to thelouvers. 'The inital water particles impihg'ing on the louver surfacestend 'to -wet these sur'faces, but as additional water .is deposited,:it accumulatesand starts to flow downwardly along the louvers. Thisflow is represented in Figure 3, and at the lower end of each louver.the water ows into the adja'cent trough 4'6. Hence, 'each troughcollects water from the adjacent row of louvers and wthn this trough thewater is no longer subjected `to the entrainin'g forces of theairstream, so that it fiows downwardly along -the troug'h to the bottomof the eliminator screen. -Here the water fiows from the eliminatorscreen to the sump tank. As shown best in figure 1, the eliminatorscreen 2'0 is .at .a small angle to the vertical, so thatit-inc linesupwardly against the air stream. This positioning of the screen .and theform and ,position of the .louvers insure that .the net effect of theactions of .gravity and the air stream s for the Water to flow down thelouvers into the troughs, and thence =down the troughs.

Referring again to Figure 4, the discussion immediately above concernsthe eliminator action at screen 30. After the air passes through screen30, itpasses on and approaches the face of screen 32. Here thewatenelimi nating action is repeated, with the air being divertedsomewhat upwardly and With any .remaining zp'articles of water impingingupon-and being deposited .upon the louvers of screen 32. Under somecircunstance's,-i-t may be desirable to provide additional screens,.butsit :has-.been found that two screens are very adequate .forthepartio ular embodiment .here being discussed.

The Suspended water particles 'are `sparated *from the air stream Withthe structure heren 'disclosed, -w'ith minimum static pressure drop, and'the water removed is not re-entrained into the air stream. The :louverspresent sufficient impingement .area to collect tthe water, and the freeopenings between them ,permit `the :air to pass. The inclination of the.louvers lengthwise, with the appropriatelyspaced Channels or troughs,nsure the removing of the moisture which is collected.

Under some circumstances, the faces, relative ,proportions andpositionings of the "louver 'may be varie'd, while not losing certain-orall of'the *advantages of 'the 'invention. The open-V trough or channelprovides a water 'stream w'hih 'tl'ows downward without 'beingdistur'bed by the air stream. Under 'some circumstances the form of thetrough may be varied and a single trough may be provided for two rows oflouvers. Also the louvers may be slanted downwardly so that they tend todeflect the air in a downward direction instead of upwardly in whichcase the louvers may be more nearly vertical to insure that the wa't'erwill flow down 'them *b'y 'surface flow. Under some circumstances 't'h'elouvers o"f 'screen 30 may be slanted as heren shown, whereas :thelouvers .in screen 32 may be slanted oppositely, "either `'downwardly orupwai-.dly :and to the ig ht in Figur 49 I As many possible embodimentsmay b'e "made in the above invention and asmany changesmight Joe :madein the embodiment above set "forth, 'it is to be understood that allmatter her'einb'eore ;set for th or shown in the accompanying drawingsis to be interpreted as illustrative and not in a limiting sense.

We claim:

;1. In -apparatus of the 'oharater described, 'an "eliminator !screen'com'prisin'g a frame Construction, 'and an eliminator screen 'supportedby 'said frame Construction formed by sheet metal 'and c'omprising a'pluralty of vertically extending rows of louvers having passagewaystherebetween and 'trough means -'adjacent eaeh of 'said rows, 'saidlouvers be-ing poitioned at an angle 'to the horizontal and extendingdownwardly toward 'said trough means whereby liqn'id 'collecting on saidlouvers fio'ws downwardly therealong tosad "trough means and 'thence in:a protected .stream 'downwardly "toward the 'bottom of said :sot-een.

2. Apparatus as described =i'ncla'im '1, where'in each of said 'louversis turned about its axis to an angle *dt sbstaiitially '45 from thegeneral plane 'of the 'screen and extends longituinally at *an an'g'le-of sdbstantially 45'? :from the horizontal.

3-. Appa'r'tis as described *in claim *1, wherein 'each df said louversh`a`s it's lower 'end extendng outwardly from :general p'l'ane of thescreen -wh'erby 'the liquid passes by surface flow to said trough means.

4. Apparatus as described in claim *3, 'w'herein said trough means is'in the form 'of -an open-V 'trough 5. Apparatu's as 'described in'claim 1, wherein said louvers are of the order of one inch in width and'said trough means is formed'in a 'strip 'of imperforate sheet metalhaving a width of the order of inch.

An'eliminatorscreen Construction'which is adapted to remove lquidparticles from 'a fast-'ilow'ing''airfstream comprising, a sheet metalscreen formed 'of'p'arallel vertical 'rows o'f louvers 'with a vertical'channel p'ositio'ned between each row and the next, said louvers 'beingpositioned'at an 'anglebPthe'order of TS 'from 'the horizontal and withthe planes slanting generally upwardly a't an ang'l'e -'from the'horizontal 'where'by "each louver resents an impacting surface tointerce'pt *liquil 'particles and li'quid accumulatinjg -"thereon flowsdownwardly to the 'ajacen't vertical channel.

a wo'oden 'franre 'providing support for said 'sheet metal I screen. I

'ke'ferences tiitea in 'the'file *Df'th'is patent 'UNITED STATES PATENTS

